Book Image

Crafting Test-Driven Software with Python

By : Alessandro Molina
Book Image

Crafting Test-Driven Software with Python

By: Alessandro Molina

Overview of this book

Test-driven development (TDD) is a set of best practices that helps developers to build more scalable software and is used to increase the robustness of software by using automatic tests. This book shows you how to apply TDD practices effectively in Python projects. You’ll begin by learning about built-in unit tests and Mocks before covering rich frameworks like PyTest and web-based libraries such as WebTest and Robot Framework, discovering how Python allows you to embrace all modern testing practices with ease. Moving on, you’ll find out how to design tests and balance them with new feature development and learn how to create a complete test suite with PyTest. The book helps you adopt a hands-on approach to implementing TDD and associated methodologies that will have you up and running and make you more productive in no time. With the help of step-by-step explanations of essential concepts and practical examples, you’ll explore automatic tests and TDD best practices and get to grips with the methodologies and tools available in Python for creating effective and robust applications. By the end of this Python book, you will be able to write reliable test suites in Python to ensure the long-term resilience of your application using the range of libraries offered by Python for testing and development.
Table of Contents (18 chapters)
1
Section 1: Software Testing and Test-Driven Development
6
Section 2: PyTest for Python Testing
13
Section 3: Testing for the Web
16
About Packt

Starting our chat application with TDD

When you start the development of a new feature, the first test you might want to write is the primary acceptance test – the one that helps you define "this is what I want to achieve." Acceptance tests expose the components we need to create and the behaviors they need to have, allowing us to move forward by designing the development tests for those components and thus writing down unit and integration tests.

In the case of the chat application, our acceptance test will probably be a test where one user can send a message and another user can receive it:

import unittest

class TestChatAcceptance(unittest.TestCase):
def test_message_exchange(self):
user1 = ChatClient("John Doe")
user2 = ChatClient("Harry Potter")

user1.send_message("Hello World")
messages = user2.fetch_messages()

assert messages == ["John Doe: Hello World"]


if __name__...